Subduction of the Nazca plate beneath Ecuador‐Colombia margin has produced four megathrust earthquakes during last century. The 500‐km‐long rupture zone 1906 ( M w = 8.8) event was partially reactivated by three thrust events, in 1942 7.8), 1958 7.7), and 1979 8.2), whose zones abut one another. Multichannel seismic reflection bathymetric data acquired SISTEUR cruise show evidence that wedge is segmented transverse crustal faults potentially correlate with limits earthquake coseismic slip...

Splay faults within accretionary complexes are commonly associated with the updip limit of seismogenic zone. Prestack depth migration a multichannel seismic line across north Ecuador–south Colombia oceanic margin images crustal splay fault that correlates seaward rupture zone 1958 (Mw 7.7) tsunamogenic subduction earthquake. The separates 5–6.6 km/s velocity, inner wedge basement rocks, which belong to accreted Gorgona terrane, from 4 5 velocity outer rocks. is dominated by basal tectonic...

[1] Tectonic processes that control the transition from poorly consolidated sediment entering subduction channel (SC) to seismogenic zone are documented using seismic imaging. We applied pre-stack depth migration and a post-processing sequence reflection line acquired across Ecuador convergent margin obtain 2D-quantitative image of first ∼24 km SC. Structural interpretation shows SC consists 630–1150-m-thick, low-velocity, continuous sheet dips ∼6° landward undergoes shear deformation. The...

Seismic records are characterized by a high level of complexity resulting from the interaction different types waves propagating in subsurface. Interpretation wave modes and features present seismic record generally is done expert judgment, its automatization problem that has not been resolved completely. We methodology uses pattern recognition to select best attributes should be chosen detect classify surface record, based on notion similarity, applied automatic interpretation three...

A seismic processing workflow based on iterative [Formula: see text] migration/inversion and target-oriented postprocessing of the migrated image is developed for fine-scale quantitative characterization reflectors. The first step involves linear iterations migration/inversion. output a true-amplitude parameterized by velocity perturbations. In second step, performed through random search with very-fast simulated annealing (VFSA) algorithm. forward problem global optimization simple...

PreviousNext No Access12th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 15–18 August 2011Near-surface S-wave velocity models from two uphole surveysAuthors: Saul Guevara*Gary MargraveWilliam AgudeloFausto GomezSaul Guevara*CREWES-University Calgary, Gary MargraveCREWES-University William AgudeloEcopetrol-ICP, and Fausto GomezEcopetrol-ICPhttps://doi.org/10.1190/sbgf2011-255 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack...

Seismic survey acquisition permits capturing subsurface data by sensing the seismic waves induced an artificial source. Hundreds of kilometers are sensed at a sampling rate that satisfies Nyquist/Shannon theorem to avoid signal aliasing, this means high-density arrangement sensors is required. In seismic, compressive imaging (CSI) framework has been developed. To test CS theory, random or simultaneous shooting techniques applied marine and land environments. For land, acquisitions require...

Physical and budget constraints often result in inadequate sampling for accurate subsurface imaging. Preprocessing approaches, such as missing trace interpolation, are typically employed to enhance seismic data cases. The compressed sensing (CS) framework has been applied modeling data, which is estimated by sparsity-based computational algorithms. While existing work mainly focuses on recovering traces resulting from receiver subsampling, source subsampling greater economical advantages,...

Seismic tomography techniques are frequently used to obtain velocity models of the weathering layer, which then calculate static corrections times. The main idea in is use misfit between synthetic and observed first-arrival (refraction) times correct an initial model. Due nature seismic method where, general, sources receivers placed on only one edge medium, Earth surface, it can be shown that inverting for velocities using does not give a unique solution. Instead, family solutions obtained...

In a 3D seismic survey, the source sampling in regular grid is commonly limited by economic costs, geological constraints, and environmental challenges. This non-uniform cannot be ignored since lack of regularity leads to incomplete data with missing 2D wavefields. Notice that postprocessing tasks have been developed under assumption are obtained from sampling. Therefore, signal recovery becomes crucial step imaging processing flow. this work, we propose pre-processing includes nonuniformly...

The Middle Magdalena Basin is an actively producing region in Colombia, which recent years has been chosen for development by means of water and steam flooding. However, complex stratigraphy challenged the a detailed reservoir static model. Tenerife 3C-3D experimental survey was conducted 2009 as integrated application (from acquisition design to interpretation) multicomponent technology differentiate lithology (sand clay) Colombian field. twice expensive conventional surveys same region, so...

PreviousNext No Access12th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 15–18 August 2011Survey geometry influence in PS wave footprint attenuationAuthors: Maria Duarte*William AgudeloAndrés CalleSaúl GuevaraMaria Duarte*Universidad Eafit;, William AgudeloInstituto Colombiano del Petróleo-ECOPETROL; Francisco Gamboa, UFBA, Andrés CalleInstituto and Saúl GuevaraInstituto UFBAhttps://doi.org/10.1190/sbgf2011-007 SectionsAboutPDF/ePub ToolsAdd...

The accurate simulation of seismic surface waves on complex land areas requires elastic models with realistic near-surface parameters. SEAM Phase II Foothills model, proposed by the SEG Advanced Modeling (SEAM) Corporation, is one most comprehensive efforts undertaken geophysics community to understand wave propagation in foothills areas. However, while this model includes a rough topography, alluvial sediments, and geologic structures, synthetic data from consortium do not reproduce...

A new parallel algorithm for shortest path ray tracing on graphics processing units was implemented. This avoids the enforcing of mutual exclusion during calculation that is found in other graph algorithms and degrades their performance. Tests with velocity models composed millions vertices a high conectivity degree show this outperforms sequential implementation.

Compressive sensing (CS) principles have been successfully tested to seismic exploration, allowing the development of a new acquisition framework. CS-based approaches attempt exploit CS reduce turnaround time and budget exploration. Different works focused on receiver-subsampling, nevertheless, sources in survey are more expensive than receivers. This work extends concept subsampling an scheme that consists multiple missing 3D orthogonal survey. The proposed removes at regular intervals...

PreviousNext No Access12th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 15–18 August 2011Comparative analysis C-wave receiver static estimation in onshore dataAuthors: Julián VargasJorge MonsegnyWilliam Agudelo*Luis MontesJulián VargasDTH-EOS Exploración;, Jorge MonsegnyDTH-EOS William Agudelo*Ecopetrol;, and Luis MontesUniversidad Nacionalhttps://doi.org/10.1190/sbgf2011-254 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack...

SUMMARY Shear wave velocity (Vs) is a fundamental property of elastic media whose estimation from PS converted waves challenging and requires modelling the boundary where P to S conversion occurs. This paper presents tomography seismic conversion/reflection points correspond reflectors modelled with level-set function set zero [ϕ(x, z) = 0]. The proposed method aims for stable Vs inversion in acquisition setting using multicomponent receivers. Synthetic models simulating true Vs, Vp location...

Polarization filters have emerged as a useful tool for coherent noise denoising in multicomponent seismic data. By exploiting the polarization properties of waves, these can significantly improve wave-type separation, which is crucial step data processing. However, their effectiveness land complex areas be impacted by presence scattering noise, and applicability limited irregular spatial sampling, hinders velocity information discrimination. To address limitations, we introduce novel...

Middle Magdalena Basin is an active producing region in Colombia, that last years has been chosen to be developed by water and steam flooding. However complex stratigraphy prevented have detailed reservoir static models. Tenerife 3D3C experiment was conducted 2009 as a first integral (from acquisition design interpretation) application of multicomponent technology discriminate lithology (sand clays) Colombian field. Acquisition resulted 480.000 traces/Km2 density, 22.3 Km2 survey....

Currently, it is necessary to reduce CO2 emissions into the atmosphere. The oil industry in Colombia can contribute through injection processes depleted fields. To achieve this, essential have knowledge of physicochemical interactions with reservoir fluids. integrate CO2, water and hydrocarbon phases, advanced models are required that capture phenomenology thermodynamic equilibrium. CPA (Cubic-Plus-Association) equation state an adds associative term model interaction phase. In this work,...

A near-surface S-wave velocity model was obtained from an uphole survey using explosive sources. Seismic events identified as S-waves were and the by picking zero offset events, analogous to method used for P-waves. These appear frequently mixed with other wave modes, which makes this procedure challenging somewhat uncertain. The complexity of wavefield increases closer energy source is surface. However, a lithological profile depth generated rock samples (drill cuttings) can be correlated...